KANSAS CITY, Mo. – The Cowboys' Ivy League-educated offensive coordinator, who just happens to be the NFL's highest-paid assistant coach at $3 million per season, crossed the fine line between confidence and arrogance last week against Denver.

This offense can't afford for Jason Garrett to do it again – even against the raggedy Kansas City Chiefs.

Garrett, once upon a time the unquestioned heir to Wade Phillips' job, has little margin for error.

He turned down offers to become the head coach of Baltimore and Atlanta after the 2007 season. After last season, he interviewed for head coaching positions with Detroit, St. Louis and Denver.

No offers came.

If the Cowboys don't make the playoffs, there's a chance he becomes yesterday's news to NFL GMs.

We all know this is a what-have-you-done-for- me-lately business. If you look at Tony Romo's regression this season, the answer is not much.

Besides, some of his players turned on him when the offense struggled last December as Dallas lost three of four games.

While the meetings with Garrett and his diva receivers were widely chronicled, don't forget Romo also indirectly criticized Garrett when he talked about a lack of adjustments and flaws in the blocking scheme.

And don't forget Ray Lewis and others talking about the ease in which they dissected the Cowboys' offense, something Denver's players and coaches echoed this week in a Sports Illustrated article.

Two weeks ago, Roy Williams proclaimed he didn't know his role in the offense, and Patrick Crayton has wondered if the Cowboys are better suited to be a power running team.

All this really means is that Garrett must do more to strengthen his players' belief in his offensive system.

It doesn't help him when Tony Romo directs 16 of his 42 passes at Champ Bailey, who has only been voted into the Pro Bowl nine times.

Dumb. Dumb. Dumb.

So was Garrett's rationale a couple of days after the Cowboys' 17-10 loss to Denver.

"We had no intention of going at Champ Bailey and no intention of shying away from him," Garrett told The News. "The way he plays gives you opportunities. He takes away some things but allows you to complete some passes, too. He's an awfully good football player. We made some plays on him and he made some plays on us."

That's the problem.

When you challenge a player of Bailey's ilk, he's going to make more plays than your guy is going to make.

His diving interception of an errant pass inside the Broncos' 10 ruined one Dallas drive, and he broke up passes on consecutive downs to end the game.

If the Cowboys still had Michael Irvin or T.O. on the roster, attacking Bailey might make sense.

But they don't.

At one level, the NFL is highly complex with its plethora of offensive and defensive schemes. At another level, the game is quite simple.

It's all about matchups.

The goal of the offensive coordinators is to attack the defense's weak link or create a mismatch the offense can exploit. Nowhere in the offensive coordinator's handbook does it say attack the defense's best player.

It doesn't take a degree from Princeton to know Garrett should attack Kansas City's worst defensive players this week. And Atlanta's worst defensive players after the bye week.

And that should be his approach the rest of the season.

Please don't misunderstand. If Garrett wants to take an occasional shot against a superior defensive player who has been ignored much of the day, then fine.

It's just not smart to attack him play after play, which allows him to find a rhythm.

It's one thing to have confidence in your players, but it's silly to think with the game on the line your fourth-best receiver will beat one of the NFL's best cornerbacks.